JSON to TypeScript Interface Converter

Generate TypeScript interfaces from sample JSON so frontend code, API clients, and data layers can share the same contract.

How to use

  1. Paste a representative JSON response that includes the fields and nesting you actually use.
  2. Open the TypeScript converter and review inferred interfaces for arrays, child objects, and scalar types.
  3. Copy the generated interfaces into your API layer or shared types module.

Benefits

  • Speeds up frontend model creation for React, Next.js, and API-heavy apps.
  • Reduces contract drift between backend payloads and frontend state.
  • Produces readable interface output that teams can review and extend quickly.

Best use cases

  • Generate frontend API response contracts for React and Next.js features.
  • Share interface definitions across service layers and UI components.
  • Catch payload drift early with strict TypeScript checks.

Type mapping notes

  • JSON numbers map to TypeScript number fields.
  • Nested JSON objects become reusable child interfaces.
  • Array item types are inferred from sample payload elements.

Implementation tips

  • Use stable root model names so imports remain predictable.
  • Enable optional generation when payload fields are conditionally present.
  • Store generated interfaces next to API client modules.

Sample JSON

{
  "id": 101,
  "name": "Ada Lovelace",
  "active": true,
  "roles": ["admin", "editor"],
  "profile": {
    "email": "ada@example.com",
    "score": 9.8
  }
}

Sample output

export interface UserModel {
  id: number;
  name: string;
  active: boolean;
  roles: string[];
  profile: Profile;
}

export interface Profile {
  email: string;
  score: number;
}

FAQ

When should I use the TypeScript interface converter instead of Zod?

Use the interface converter when you need static typing only. Choose Zod when you also need runtime validation.

Does the TypeScript converter support nested arrays and child objects?

Yes. Nested objects and arrays are expanded into reusable interface definitions based on the sample payload.

What to expect on this route

Use the TypeScript converter when you need readable frontend contracts from a representative JSON sample and want to confirm the inferred model shape before copying it into code.

What makes a good sample

  • Include the nested objects, arrays, and optional fields your app actually consumes.
  • Keep the payload realistic so the generated interfaces reflect production field names and shapes.
  • Prefer one stable example over many partial fragments when you want predictable output.

What the converter returns

  • Nested child interfaces are inferred from the JSON structure in the sample payload.
  • Scalar values map into TypeScript-friendly field types that stay readable in frontend code.
  • The output remains copy-ready so it can move straight into shared types or API client modules.

Checks before you copy

  • Review optional fields carefully when the sample can omit values in some responses.
  • Rename the root model if your project uses a stronger domain-specific naming convention.
  • If you also need runtime validation, move from plain interfaces into a stricter schema route afterward.